In optimization applications, these decisions are usually governed by multiple overlapping sets of rules and costs. These rules represent both challenges and opportunities.

The challenges are to find the best solutions that follow all of the rules. The opportunities are to try different combinations in different circumstances that follow the rules and maximize the formal objective function: typically, greatest asset utilization and maximum profit.

At Princeton Consultants, we group these rules/costs into: physical, regulatory, contractual, marketplace, policy, and practical.

Regulatory: Vehicles and machinery often are subject to regulations that can be complex, for instance the airline, in selecting a plane and airport, must respect minimum runway lengths for different types of planes in different weather conditions and weights.

Contractual: For magazines, the printing company must closely coordinate its binding to be at the exact day and sometimes time of day with the printing presses and the outbound transportation.

Marketplace: For the pharmaceutical company, demand for individual allergy tests varied by season, therefore allowing us to help its management optimize by configuring the machines in advance to the most efficient setup for forecasted demand.

Policy: For the business publication, it is company policy not to run advertisements on the same pages as news stories that concern that company, a competitor, or its industry.

Practical: In the service network company, changing configurations too often would drive down the efficiency of the operations staff, so Princeton Consultants added a cost into the optimization that would be unafraid to make network routing changes, while at the same time reflecting true and nuanced costs.